An excerpt from the book Advanced Handwriting Cryptography..
A simple signature is easy to fake. There are secure digital signatures in use these days but all human legal transactions will never be digitally confirmed. Common handwriting signature will remain in use. Here the cryptic signature may come for help against misuses. A cryptic signature will be harder to fake and it will also provide a level of confidentiality, in cases where the name isn’t written on the document but only a signature is required. For using a cryptic signature there can be used the most basic version of the advanced encryption method (described in chapter 17.1), which takes only a few minutes to create when you have done it before. You can change the cryptic signature while it remains yours. You can create the key of the code in a small piece of hard paper, protect it with a plastic cover, and carry around like other documents. When an occasion demands to sign something and it’s permitted to do it in encrypted way to hide your name from others who sign the same paper, then instead of your known signature you can create a cryptic signature on the spot, using the key you carry with you. Then in another document you can use a different cryptic signature so others can’t relate the documents as both been signed by you. But then needed to prove the authenticity of your signature you will prove it with your key, which isn’t secret but simply not available to anyone, like your passport. The key can be copied and kept in a secure location as a backup in case of loss, and you don’t need to write your name on the key. Anyone who finds the lost key will not know to whom it belongs, so a deliberate forgery of a signature becomes impossible — the person who finds the key won’t know the person to forge the signature, except stealing the key directly from the owner of the key. And even then it will be impossible if the owner of the key won’t have the full key written down, keeping few extra elements in memory, for safety. At the same time, anyone who finds the key can use it (even if the key is incomplete, without the extra safety elements) for securing his/her own signature (adding personal safety elements), or for sending lightly secured messages to someone having the copy of the same key. The probability of accidentally having identical key with someone else, an unwanted party, is extremely low even without the additional safety elements which are created by each user of the same key and memorized. the code won’t be unbreakable though, by other users of the same key, but that isn’t needed for signature — you only need the protect your signature against forgery. A cryptic signature is definitely safer than a simple signature. You can create several different cryptic signatures in advance the design you like and to practice them for a bit. Then you won’t have to invent a cryptic signature by the key on the spot, but use one of the available cryptic signatures which you use in different occasions, all of them valid.. or even a non valid signature if needed due to some social pressure, if you can’t refuse a thing that others demand you to sign, so if later you’ll get into a complicated situation you simply won’t recognise the signature as yours. For using your cryptic signature on an official document with your written name on it the key of the cryptic signature must be registered in some ways, for not claiming later that the signature isn’t yours, and the authorities must be capable of verifying the signature with the key, I suppose, but that’s not absolutely necessary because in these occasions you can use your regular signature.